The effective supply of bitcoins can increase if we invent ways to trade existing bitcoins faster (such as convenient apps or exchanges). This is why the Feder

The effective supply of bitcoins can increase if we invent ways to trade existing bitcoins faster (such as convenient apps or exchanges). This is why the Federal Reserve needs to know the "velocity of money" when determining how many dollars to put out there -- half the dollars moving around twice as fast is effectively the same availability of money. A similar thing happens if people end up issuing bitcoin-denominated debt instruments and then trading those rather than bitcoins directly. A good example is if you and I both have 100 bitcoins in our accounts at a bitcoin bank and I send my coins to you -- the bank could do that transaction without having the 100 bitcoins in reserve.